The Hindu Business Line : Feeble ‘low’ may see north-west dry up faster

Thiruvananthapuram, Sept 23 The feeble ‘low’ that has formed afresh in the North Bay of Bengal would once again help propel fairly widespread rainfall with isolated heavy falls over West Bengal, Sikkim and coastal Orissa. It clearly lacks the punch to drive any further into the country’s farming heartland, thus beckoning the seasonal anti-cyclone (high pressure area with dry weather) to advance in from extreme west Rajasthan.

While no numerical models seem to suggest another round of activity in the Bay, forecasters are watching with interest the progress of Hagupit, a Category-3 storm raging currently in the Northwest Pacific and aiming to hit the south-east China coast. Hagupit has been moving in a west-northwest direction after hitting the Philippines, and will be monitored for signs of re-generation as a stray circulation in the South China Sea or the Bay of Bengal.

DRY PHASE

According to the Climate Prediction Centre of the US National Weather Service, there is an increased chance for below-average rainfall for equatorial Indian Ocean, southern India (the whole peninsula) and west Indonesia during the week ending September 30. This has been attributed to the suppressed phase of the Madden-Julian Oscillation (MJO) wave, whose enhanced phase marked by convection and rain might gradually make is presence felt during the immediate next week (September 30-October 6).

This forecast ventures to suggest “increased likelihood of further increase in convection as we move into the next week” (October 7 to 13). This should set the stage for the scheduled onset of the northeast monsoon around mid-October.

The positive MJO wave is also forecast to settle over the area around this time, but for the northeast monsoon (reverse monsoon) to get going, predecessor southwest monsoon should have withdrawn completely from the landmass.

In this manner, the southwesterly wind regime must yield place to the northeasterly winds at the lower levels. September 30 is the normal date for this to happen but is way behind schedule at least as of now.

India Meteorological Department (IMD) expects that parts of northwest India – north Gujarat and Rajasthan – might witness the monsoon withdraw over the next few days.

The Global Forecast System of the US National Centres for Environmental Prediction says that the seasonal dry weather would have engulfed North Gujarat, Rajasthan, Haryana, Punjab, Delhi and west Uttar Pradesh by September 30.

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